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22 Cards in this Set
- Front
- Back
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Magnetic poles
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*every magnet has two, north and south
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magnetic
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* the ability to exert forces on magnets or other magnetic materials
*can create magnetic effects by itself. |
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Permananet magnets
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*a material that keeps its magnetic properties, even when it is not close to other magnets.
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Poles
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*all have magnetic poles, north and south.
*if cut in half, it still has poles |
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magnetic force
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*opposite poles attract
*same poles repel |
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materials are transparent to magnetic forces
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*magnetic forces can pass through many materials with no apparent decrease in strength.
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the magnetic field:
how to describe magnetic forces? |
*forces are generated between 2 magnets.
* a way to find the force is with a long complicated formula (scientific method) OR *an ease way-to get another magnet that is small enough not to affect the magnetic force. |
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drawing the force
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*the magnetic force of a magnet points away from the north pole and toward the south pole of the magnet.
*this is because the north pole of the test magnet repelled from the north and attracted to the south pole. |
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the magnetic field
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*the drawing is called a magnetic field.
*the quantity that has a value at all points in space. *creates a magnetic field and then the field applies a force on another magnet *can be call a "force field" created by a magnet |
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paramagnetic
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*example: aluminum
* the magnetism of individual electrons does not cancel completely. |
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soft magnet
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*example: steel
* a magnet that is easy to magnetize but loses its magnetization easily. *heat, shock, and other magnets demagnatize steel |
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ferromagnetic
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*small group of metals that have strong magnetic properties
examples: iron, nickel and cobalt |
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hard magnets
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*materials that make beeter permanent magnets.
*the domains in hard magnets tend to remain aligned for a long time. *strong electromagnets are used to magnetize hard magnets. |
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field lines
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*the source magnet creates the magnetic field and the magnetic field lines run from the north pole of the magnet to the south pole of the magnetic field.
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electromagnets
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*are magnets created by electric current flowing in wires.
*a simple example: a coil wrapped around an iron core |
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right hand rule
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*use the fingers of your R hand - curl in the direction of current, your thumb points toward the magnets north pole.
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diamagnetic
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*in many elements the magnetic field of individual electrons in each atom cancel with each other.
This leaves the whole atom with zero met magnetic field. |
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ways to demagnetize
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*heating them, shocking them, dropping them, subjecting them to a stronger magnetic field.
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ways to increase strength of a magnet
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*increase turns, and use more permeable core material
*refer to the book/ pg 365 in the book) |
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What are magnetic domains?
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*groups of neighboring atoms whose magnetic fields are similarily aligned.
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source of magnetism
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*magnetism is created by moving charges, either in an electric current or in the atoms that make up material.
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